If you installed vmware server edition, there should be a command named vmware-vdiskmanager. You can use vmware-vdiskmanager to convert several vmdk image into one vmdk image and raw image.
VMware Virtual Disk Manager - build 44356.
Usage: vmware-vdiskmanager OPTIONS diskName
Offline disk manipulation utility
Options:
-c : create disk; need to specify other create options
-d : defragment the specified virtual disk
-n <source-disk> : rename the specified virtual disk; need to
specify destination disk-name
-q : do not log messages
-r <source-disk> : convert the specified disk; need to specify
destination disk-type
-x <new-capacity> : expand the disk to the specified capacity
Additional options for create and convert:
-a <adapter> : (for use with -c only) adapter type (ide, buslogic or lsilogic)
-s <size> : capacity of the virtual disk
-t <disk-type> : disk type id
Disk types:
0 : single growable virtual disk
1 : growable virtual disk split in 2Gb files
2 : preallocated virtual disk
3 : preallocated virtual disk split in 2Gb files
The capacity can be specified in sectors, Kb, Mb or Gb.
The acceptable ranges:
ide adapter : [100.0Mb, 950.0Gb]
scsi adapter: [100.0Mb, 950.0Gb]
ex 1: vmware-vdiskmanager -c -s 850Mb -a ide -t 0 myIdeDisk.vmdk
ex 2: vmware-vdiskmanager -d myDisk.vmdk
ex 3: vmware-vdiskmanager -r sourceDisk.vmdk -t 0 destinationDisk.vmdk
ex 4: vmware-vdiskmanager -x 36Gb myDisk.vmdk
ex 5: vmware-vdiskmanager -n sourceName.vmdk destinationName.vmdk
